ES2200846T5 - ARTICLE WITH BALISTIC RESISTANCE THAT INCLUDES A FLEXIBLE FABRIC FABRIC FABRIC AND MATRIX OF DISCONTINUOUS DOMAINS. - Google Patents

Abstract

A composite having a plurality of filaments arranged in a fibrous web that is held together in a unitary structure by a domain matrix. The domain matrix comprises a plurality of matrix islands that individually connect, or bond, at least two filaments, to thereby hold the filaments in a unitary structure. Portions of the filament lengths within the unitary structure are free of matrix islands, causing the domain matrix to be discontinuous. The composite possesses a greater flexibility than coated structures. The composite may be formed into cross-plied structures. A method of making the composite also is disclosed.

Description

Article endowed with ballistic resistance that comprises a flexible fabric of fibrous tissue and domain matrix discontinuous

Background of the invention Field of the Invention

The present invention relates to systems continuous layers of integrated fiber layers with material domains that matrix islands forms, and more particularly to a method of manufacture of continuous systems of fiber layers that held together with matrix islands and compositions of systems layers of continuous fibers meshed with matrix islands. The fiber layer systems of the present invention provide high strength composite materials with characteristics of flexion and resistance especially useful in flexible items highly impact resistant.

Background of the invention

Items designated to withstand impacts ballistics, such as bulletproof vests, helmets, equipment body protection, shields and other police and military equipment, structural members of helicopters, aircraft, ships, and vehicle panels and briefcases containing high fibers Resistance, they are known. High strength fibers known include aramid fibers, fibers such as poly (phenylenediamine-terephthalamide), ultra-high molecular weight polyethylene, fibers Graphite, ceramic fibers, nylon fibers, glass fibers and analogous The fibers are generally encapsulated or embedded in a continuous structure of matrix material and, in some cases, they are joined with rigid facing layers to form structures complex of composite material. The shield should provide protection against ballistic projectiles such as bullets and other similar penetrating objects or projectiles of the technique previous. However, body protection equipment, bulletproof vests, etc. they can be rigid and restrict the user movement.

Articles of composite materials endowed with ballistic resistance have been described in US Patents of Harpell et al . No. 4,403,012; 4,501,856 and 4,563,392. These patents describe cellular structures of high strength fibers in matrices composed of olefinic polymers and copolymers, unsaturated polyester resins, epoxy resins, and other resins capable of curing below the melting point of the fiber. While such composite materials provide effective ballistic resistance, AL Lastnik et al .: "The Effect of Resin Concentration and Laminating Pressures on Kevlar Fabric Bonded with Modified Phenolic Resin", Technical Report NATICK / TR-84/030, June 8, 1984 , has described that an interstitial resin, which encapsulates and bonds the fibers of a fabric, reduces the ballistic resistance of the resulting composite article. Therefore, there is a need to improve the structure of composite materials to effectively utilize the properties of high strength fibers.

US Patent No. 4,623,574, of Harpell et al ., Filed on January 14, 1985, and assigned to the same assignee of the present invention, describes simple composite materials comprising high strength fibers embedded in an elastomeric matrix. Surprisingly, the simple composite structure exhibits outstanding ballistic protection compared to a simple composite material that uses rigid matrices, the results of which are described in that document. Simple composite materials that employ ultra-high molecular weight polyethylene and polypropylene such as are described in US Patent No. are particularly effective. 4,413,110.

Composite materials that have domains Continuous are described in the art, generally being restricted the percentage of resin so that it is at least 10% by volume of the fiber content U.S. Patent No. 4,403,012 describes a matrix in the preferred range of 10-50% by weight of fibers. U.S. Patent No. 4,501,856 describes a content of the preferred fiber cell structure of 40 to 85 percent in volume of composite material. U.S. Patent No. 4,563,392 no describes any interval for the quantities of a component of matrix. It is desirable to keep a percentage of fibers in volume and / or weight as high as possible within a composite resulting to improve ballistic resistance.

U.S. Patents No. 5,061,545 and 5,093,158, both assigned to the same assignee of the present invention, describe a fiber / polymer composite with matrix non-uniformly distributed polymer, and a method of Composite material manufacturing. These patents are aimed at a fibrous tissue that has a cellular fiber structure uni-directional, and a matrix composition distributed unevenly, but continuously, in the major plane of fibrous tissue. The fibrous tissue is enclosed in the matrix composition, and although not uniformly distributed, the matrix composition is maintained as a continuous whole, which It is attached to all fibrous tissue fiber members. The patents describe polymer compositions distributed so non-uniform along with a fibrous tissue such that there is a surface fitted to a pattern, which makes certain portions of the resulting combined tissue have higher amounts of polymer than other portions. This reduced the total amount of polymer needed to maintain tissue integrity impregnated with polymer. The patents further described that thick areas that provide the integrity of the layer of polymer preferably provide a continuous area along the surface of the fibrous / polymer composite.

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Other patents, such as U.S. Pat. Do not. 4,623,574, have demonstrated the difficulty in preparing a composite material made of a fabric fabric within a matrix of polymer. In Table 6 shows 12, when a high amount of fiber, the sample lacked consolidation and not He could undergo the trials.

U.S. Patent No. 3,686,048 describes a composite material comprising a plurality of parallel fibers that are held together by resin bridges between two or more adjacent filaments.

The cost and quality of the fabric also affect to the availability of shielding. The cost of a conventional fabric increases dramatically as the thread denier decreases. Additionally, both ballistic efficiency and flexibility improve as the surface density of the layers decreases individual.

Summary of the invention

The present invention is a designated article to resist ballistic impacts, selected from a vest bulletproof, a helmet and body protection equipment, as defined in claim 1. The array of domains provides islands of fixed matrix, or anchor points, within the fibrous tissue, which join portions of the fibrous tissue into a unit structure. The matrix islands can join as few as two filaments in the fibrous tissue, or they can join as many as all of the filaments of fibrous tissue, including its conformation as a continuous cord (very long domain). With number, size, shape and Sufficient distribution of matrix islands, filaments individual within the fibrous tissue form a structure unitary.

A fibrous tissue is a layer defined by a plurality of fibers. Typically, the layer is thin and defines a surface, having a depth of at least one filament. He fibrous tissue is a tape or layer in which the fibers are uni-directional. By uni-directional it is understood that the fibers are parallel to each other within the tissue, or that the fibers are They extend along a given directional axis, without overlapping. Matrix islands are defined as anchor points that they retain,  and preferably join two or more filaments together, forming each matrix island separated, or discontinuous from other matrix islands A spatial distribution Collectively, the matrix islands they constitute a matrix of domains that binds fibrous tissue as A unitary flexible structure. The matrix islands may be distributed within the array of domains in regular patterns and / or random. The amount of polymer material in the matrix of domains is small enough to make them present fiber areas without matrix (hereinafter referred to as "fiber without coating "or" uncoated filaments "). fiber fabrics can be folded cross to form panels flexible

The composite material used herein invention comprises a plurality of fibers, arranged preferably along a single directional axis, in which the plurality of fibers are essentially parallel to each other, and matrix islands that cut at least a portion of the plurality of sufficient fibers to retain, and preferably bond, the plurality of fibers in a unitary structure, in which the plurality of fibers possesses flexibility outside the plane.

Additionally, the composite material used in the present invention it can be manufactured by a method comprising the steps of arranging a plurality of fibers in a layer, and place a plurality of matrix islands within the plurality of fibers so that each matrix island cuts a sufficient portion of the plurality of fibers in order to retain, and preferably joining, the plurality of fibers in a structure unitary.

The composite material used herein invention can form a flexible tape, uni-directional (referred to also as "uni-tape") that can be used as a precursor in conventional textile processes of extension of tapes or filament winding. The shapes of the section Transverse composite material may vary with use, such as a flat ribbon shape, elliptical shapes, circular shapes, and special forms that are preferable for given textile processes such as braiding and knitting. You can combine layers of flexible prepreg material to form bent products in cross.

The composite material of fibrous tissue and matrix domains used in the present invention maintains the tissue integrity but results in a composite material with significant advances in the volumetric ratio of fiber to polymer compared to that previously known in the art. These structures are ballistically efficient and very flexible, With capacity to let water vapor pass.

Brief description of the drawings

Fig 1 is a top view of a fabric fibrous preferred with random matrix islands that form a uni-directional structure;

Fig 1A illustrates the domain matrix of Fig. one;

Fig 2 is a top view of a matrix of non-random matrix island domains that bind filaments in a uni-directional structure;

Fig 3 illustrates a top view of the shape of the matrix islands along the length of two tapes uni-directional cross bent 90º of Fig. one;

Fig 3A illustrates a top view of the shape of a simple matrix island;

Fig 4A shows an isometric view in neat exploded view of a composite structure 0/90 folded in cross of two layers of the structure of Fig. 1;

Fig 4B shows a top view of Fig. 4A;

Fig 4C shows a side view of Fig. 4A;

Fig 5A shows a side view of Figs. 4A-4C with an outer film layer;

Fig 5B shows an isometric view in exploded view of Fig. 5A;

Fig. 6 shows a top view of a cross bent structure of the ribbons uni-directional;

Fig 7 is an illustration of a method Preferred manufacturing of the composite material of the present invention; Y

Fig. 8 is an illustration of a method of alternative preferred manufacture of the composite material of the present invention

Detailed description of the invention

The present invention is directed to a article as defined in claim 1. The material compound contains a plurality of filaments in the form of fibers parallel, referred to as a set of parallel filaments, fixed in the domain matrix. The matrix of domains is constituted by a plurality of matrix islands, preferably made of polymer material, distributed spatially within the array of domains. The matrix islands anchor and hold together the fibrous tissue filaments as a unitary structure These anchors positionally fix the individual filaments of the fibrous tissue in relation to each other, if well they allow the combination to fold. The total volume of matrix islands along a given area of fibrous tissue taken as a fraction of the fiber volume defines the density of volumetric relationship of the domain matrix (V_ {m} / V_ {f}).

The matrix islands of the array of domains do not are physically connected to each other, except for the filament material As such, the domain matrix comprises a discontinuous polymer material, or "island." However, since matrix islands permanently anchor fiber locations specific, the domain matrix is a fixed structure. The discontinuous structure of the domain matrix allows for greater volume percentage of fibers in the composite material that I would make a continuous matrix composition. Additionally, it is created a robust structure, that is to say that the array of domains sets the fibers of a unit structure that is easily handled without tendency to separate or disperse.

The discontinuous structure of the matrix of domains produces isolated domains within the prepreg  and products manufactured from them. The isolated domains, that leave important sections of fibers uncoated, or without matrix material, are necessary to improve the bending of the composite material. The amounts of the domain matrix used must be small enough to provide  a segment of uncoated filaments in the material prepreg and the resulting products, and may include those quantities that promote matrix-free areas. The volumetric ratio (V_ {m} / V_ {f}) can be as high as 0.5 provided that the fibers and polymer material produce so compatible areas of uncoated filaments; However, the domain matrix is preferably present in amounts expressed in volumetric ratio between about 0.4 or less, more preferably about 0.25 to about 0.02, and most preferably about 0.2 to about 0.05. Providing a spatial distribution of matrix islands, can be incorporated extremely high volumes of fiber to form a structure which has improved physical integrity during processing and the use, such as handling and cutting of composite material, and overlay of prepreg tape uni-directional The structure of fibrous tissue resulting maintains flexibility of uncoated fibers combined within the fibrous tissue. For the expression maintenance of its integrity and aptitude for manipulation, it is understood that the fibrous polymer composite retains its structure without wire separation during processing and use. More of a layer of resin-bound fibrous tissue can accumulate to form a diversity of multilayer laminates, such as 0/90, + 45 / -45, + 30 / -30, 0/60/120, 0/45/90/135, etc. It has been found that these laminates of multilayer composite material are impact resistant, and more specifically impact resistant ballistics

Each section of fibrous tissue of the material compound of the present invention has a spatial distribution of polymer, or matrix islands, which it retains (preferably binds) two or more fibrous tissue filaments together, providing areas With and without polymer material.

Fig. 1 illustrates a composite material 10 that it comprises a fibrous tissue 12 and an array of domains 14. The fibrous tissue 12 is made of filaments 16 that are oriented uni-directionally. The array of domains 14, which is shown separately in Fig. 1A and comprising matrix islands individual 18, is structured within the fibrous tissue 12, and defined therein by the fibrous tissue 12. As seen in the Figs. 1 and 1A, although domain matrix 14 joins the filaments individual 16 in relation to each other, is the location of the filaments 16 which defines the location of the matrix islands 18.

As previously stated, the matrix of domains 14 is formed by the combination of matrix islands 18 and It exists as a discontinuous matrix of polymer material. The uncoated filaments 16 fixed by matrix islands 18 allow dimensional flexibility of the prepreg cone material previously known. The structure of the present invention It allows the transmission of gases and liquids.

In one embodiment, the matrix islands 18 are randomly and / or irregularly spaced within the fibrous tissue 12, over the entire length of the fibrous tissue 12. Each matrix island 18 retains the relative positions of at least two filaments 16, and can retain relative positions of up to all 16 filaments in the uni-directional tape. The matrix islands 18 are preferably sized so that are not thicker than a bundle of filaments 16 within a fabric 12, since the additional polymeric material would tend to fill the empty areas of fibrous tissue 12. Collectively, the distribution random matrix 18 islands provides a matrix of supportive domains 14 that retains fibrous tissue 12 in a unitary structural configuration. Different sections of tissue Fibrous 12 may possess varying amounts of polymer material, in size and / or spatial density of the matrix islands 18. Without However, a given fibrous tissue 12 generally has a size medium, size distribution, average distance between the islands of matrix 18 and other statistical characteristics of the islands of matrix 18 over the entire length of the composite material that They provide specific properties. The sizes of the islands of matrix 18 should also be relatively small in relation to the size of the striking projectile, given that the matrix islands 18 smaller in size they control the position better locally space design of closely spaced parallel filaments on the scale of the striking projectiles. The Matrix Islands 18 they should be small compared to the radius of curvature desired of a specific fabric. The uncoated filaments 16 between matrix islands 18 allow tissue flexibility fibrous 12, while the areas that constitute the islands of matrix 18 remain as anchor points that maintain the multiple filaments within fibrous tissue 12 in a relationship fixed with respect to each other. The average size of the islands of matrix is less than about 5 mm in at least one direction, more preferably less than about 3 mm, so even more preferable less than about 2 mm, and very preferably less than 1 mm. Although the areas with the composition Polymer are not as flexible as matrix free areas, the areas with the polymer composition preferably impart flexibility to fibrous tissue 12. Most of the lengths 16 of the filaments are preferably free of matrix, and by consequently the fibrous tissue 12 of the present invention can move more easily than a tissue in which the fibers are totally enclosed in a matrix.

In another embodiment, shown in Fig. 2, the matrix islands 18 are evenly spaced in the fibrous tissue 12 within matrix areas of discrete domains 14, along the entire length of the fibrous tissue 12. In extended lengths equal, represented as the length A, of the fibrous tissue 12, the spatial density of the matrix islands 18 remains generally constant. However, at shorter lengths of fibrous tissue 12, represented as length B, the spatial density of matrix islands 18 may vary markedly. The matrices
domains 14 may be continuous from one side to the other of a uni-directional tape, as shown in Fig. 2.

The shape of the matrix islands 18 follows generally the surface line of the fibers, as shown in Fig. 3, with matrix island 18 in the filament of the upper layer 16 represented in solid line and matrix island 18 in the filament of the bottom layer 20 represented in line imaginary The size of matrix 18 islands among the filaments 16, on average, is a sufficient quantity to join adjacent layers and maintain structural integrity during the use. The size, shape and spatial density of the islands of matrix 18 within the fibrous tissue, or prepreg, dictate the formation of uncoated filaments in a product final. The shape of the matrix islands 18 provides the degree of tolerable flexion for a given section of fibrous tissue 12, while still retaining functional attributes as points of anchor for individual filaments 16. Distribution space of matrix 18 islands provides integrity structural in a distortion perpendicular or from another angle to the filament direction 16 while spatial density provides differentiated characteristics of fibrous tissue unified 12.

As seen in Fig. 3, the shape of the island of individual matrix 18 is elongated, advancing its dimension longitudinal in the same direction as, or parallel to, the length of the filament 16. The elongated shape of the matrix islands 18 is caused by a wet phenomenon, when the matrix droplets (latex suspension in water or matrix solution) touch the filaments The droplet is then dispersed in the space between the filaments, trying to reduce surface energy. The relationship of dimensions, or proportions of length and width (l / w) that are shown in Fig. 3A, of matrix islands 18 may be useful as over an extensive range of quantities targeted for uses individuals, which include non-exclusive relationships of about 35: 1 to about 1: 1, about 20: 1 a about 1: 1, about 10 to about 1: 1, and / or from about 3: 1 to about 1: 1. Although the forms Elongated are the most common, regular shapes can be used and irregular, examples of which include, without limitation, forms regular such as donuts or atolls, rectangles, squares, circles, ellipses, etc., and irregular shapes such as islands asymmetric With the 20 crossed filaments used in a composite structure folded in cross 30, the island of matrix 18 advances along the length and is fixed to both filaments 16 and 20. The diameter of the matrix island 18 at the point of intersection 22 between filament 16 and cross filament 20 determines the adhesion of the panels uni-directional (or fibrous tissues) when they are formed in cross-layer configurations. The forms of uni-ribbon and folded cross present invention provide extremely flexible porous structures. When the uni-directional tape that has a polymer material protruding on one side bends cross with a second uni-directional tape, the particles individual polymer material are compressed on both tapes uni-directional. The resin, which flows preferably along the fiber direction of each uni-directional tape, forms a cross figure. In each surface of an elongated domain, the elongated domain is formed with the major axis parallel to the direction of the fiber. With a panel 0/90 or + 45 / -45, the elongated domains are superimposed and oriented at right angles to each other.

Figs. 4A-4C illustrate a preferred embodiment of the tapes uni-directional of Fig. 1 formed in a cross layer configuration. As seen in Fig. 4A, the tapes 32 and 34 are stratified with their respective filaments perpendicular to each other, e.g., in a provision 0/90, + 30 / -60, or + 45 / -45. The matrix 18 islands, which form an array of domains 14, join the filaments 16 into tapes uni-directional 32 and 34, joining at the same time tapes 32 and 34 with each other. Additional tapes can be arranged in one or both sides of tapes 32 and 34 with the same or another orientation, such as in a -45 / + 45 configuration. Fig. 4B is a top view of Fig. 4A showing the upper belt 32 with matrix islands 18 in a discontinuous pattern in them. Fig. 4C is a side view of Fig. 4A showing filaments 16 in the upper belt 32 and the lower belt 34 joined by islands of matrix 18.

As seen in Figs. 5A and 5B, in some cases it is desirable to have a surface film on the panels to reduce the chance of the fibers getting caught or simple filaments and deterioration of the panels during their normal handling Fig. 5A shows a side view of a upper belt 32 and a lower belt 34 made of filaments 16 arranged between two films 100 and 102. Tapes 32 and 34 and the movies 100 and 102 are linked together by matrix 18 islands, that collectively form an array of material domains compound. Fig. 5B is an isometric exploded view of Fig. 5A, showing tapes 32 and 34 fixed by the islands of matrix 18, with upper 100 and lower 102 films fixed also for matrix 18 islands. For maximum flexibility, the films are preferably thin and are joined by points to the tapes

Fig. 6 shows a folded cross structure with the matrix islands 18 extending across the width of ribbon 34. The extended matrix 18 islands are maintained discontinuous with respect to each other even with the application of a second tape 32. Very narrow elongated matrix domains 14 that intersect as straight lines throughout the multitude of fibers parallel in the uni-directional tape are perpendicular to the set of fibers or are arranged in a angle (var), preferably from about 10 ° to approximately 170º, more preferably from approximately 30º to approximately 150º, or as curved lines that include patterns created by circles, ellipses, ovals, or figures multiple geometric

The high strength fibers of the present invention preferably have a tensile modulus of at least approximately 160 g / denier and a toughness of at least approximately 7 g / denier in a polymer matrix or domain 14 adequate. The polymer composition of the domain matrix 14 Can comprise an elastomer, thermoplastic elastomer, material thermoplastic, thermosetting material, and / or combinations or mixtures thereof. Preferably, the polymer composition It comprises an elastomeric matrix material. The fiber is tested from according to ASTM D 2256 using 4D rim and cord clamps, in an Instron RTM testing machine, for elongation of 100% / minute It is preferred to have an elastomeric composition with a tensile modulus less than 20,000 psi (138,000 kPa) preferably less than 6,000 psi (41,400 kPa) measured accordingly with ASTM D 638-84 at 25 ° C.

The filaments 16 of the present invention are elongated bodies of considerable longitudinal dimension in relation to its transverse dimensions of width and thickness. He The term fiber does not exclusively include a monofilament, multifilament, thread, tape, band, and similar structures that they have areas of regular or irregular cross section. The tissue fibrous 12 for the purposes of the present invention comprises any group of fibers useful for making tape uni-directional or cross-layer structures. He Preferred fibrous fabric 12 comprises weight polyethylene fiber Highly oriented ultra-high molecular fiber, fiber of ultra-high molecular weight polypropylene highly oriented aramid fiber, poly (alcohol fiber) vinyl), polyacrylonitrile fiber, polybenzoxazole fiber (PBZO), polybenzothiazole fibers (PBZT) or combinations of same. It is generally understood that weight polyethylenes Ultra-high molecular include molecular weights from about 500,000 or more, more preferably from about 1 million or more, and most preferably older that approximately 2 million, up to a magnitude of Approximately 5 million The tensile modulus of the fibers, as measured by an Instron tensile testing machine, it is usually at least about 300 g / denier, so preferably at least about 1000 g / denier and so very preferably at least about 1500 g / denier. The tenacity of The fibers is usually at least about 15 g / denier, more preferably at least about 25 g / denier, of even more preferably at least about 30 g / denier, and most preferably at least about 35 g / denier. The ultra-high molecular weight polypropylenes they have a weight average molecular weight ranging from about 750,000 or more, more preferably since approximately 1 million or more, and most preferably greater than approximately 2 million. As polypropylene is a material much less crystalline than polyethylene and contains methyl groups pendants, the tenacity values that can be achieved with polypropylene are as a rule substantially lower than the corresponding values for polyethylene. A tenacity suitable for polypropylene can reach from at least approximately 8 g / denier, with a preferred toughness at least 11 g / denier The tensile modulus for polypropylene is at least about 160 g / denier, preferably at least approximately 200 g / denier. The melting point for polypropylene generally increases several degrees by the orientation process, of such that the polypropylene fiber preferably has a main melting point of at least about 168 ° C, so more preferable at least about 170 ° C.

Aramid fiber is mainly formed by aromatic polyamides. Aromatic polyamide fibers that they have a module of at least approximately 400 g / denier and Tenacity of at least about 18 g / denier are useful for Incorporation into the composite materials of this invention. Fibers Illustrative aramid include fibers of poly (phenylenediamine-terephtal-amide) produced commercially by DuPont Corporation of Wilmington, Delaware under the trade names of Kevlar® 29, Kevlar® 49 and Kevlar® 129.

Polyvinyl alcohol (PV-OH) fibers are useful for weight average molecular weights of at least about 100,000, preferably at least 200,000, more preferably between about 5,000,000 and about 4,000,000, and so very preferable between approximately 1,500,000 and approximately 2,500,000. Usable PV-OH fibers should have a modulus of at least about 60 g / denier, preferably at least about 200 g / denier, more preferably at least about 300 g / denier, and a toughness of at least about 7 g / denier, preferably at least about 10 g / denier, more preferably at least about 14 g / denier and most preferably at least about 17 g / denier. PV / OH fibers having a weight average molecular weight of at least about 500,000, a toughness of at least about 200 g / denier and a modulus of at least about 10 g / denier are particularly useful in the production of endowed composite materials of ballistic resistance. PV-OH fibers having said properties can be produced, for example, by the process described in US Patent No. 4,559,267, issued to Kwon et al ., Assigned to the same assignee of the present invention.

Detail about the filaments of polybenzoxazoles (PBZO) and polybenzothiazoles (PBZT), can found in "The Handbook of Fiber Science and Technology: Volume II, High Technology Fibers ", Part D, edited by Menachem Lewin, which is incorporated herein by reference.

Fibers of polyacrylonitrile (PAN) having a molecular weight of at least approximately 400,000, and preferably at least 1,000,000. They are particularly useful PAN fibers having a toughness of at less about 10 g / denier and a breaking energy of at minus about 22 joule / g. A PAN fiber that has a molecular weight of at least about 400,000, a toughness of at least about 15-20 g / denier and a Breaking energy of at least about 22 joule / g is extremely useful in the production of articles with resistance ballistics, such fibers being described, for example, in the U.S. document Pat. No. 4535027.

For the purposes of this invention, a layer fibrous comprises at least one fibrous tissue of isolated fibers or with a matrix. The fibers include one or more filaments 16. Fiber denotes an elongated body, whose longitudinal dimension is much greater than the transverse dimensions of width and thickness. From accordingly, the term fiber includes monofilament, multifilament, tape, band, running fiber and other forms of chopped, cut or discontinuous fiber and the like that have regular or irregular cross sections. The term fiber includes a plurality of any one or a combination of the previous.

The cross sections of the filaments for use in this invention may vary widely. Fibers they can be circular, flat or oblong in cross section. The they can also be of multilobular cross section irregular or regular, having one or more regular lobes or irregular protruding from the linear or longitudinal axis of the fibers Particularly, it is preferred that the filaments be of substantially circular cross section, flat or oblong, very preferably the first.

The fibers are aligned uni-directionally so that they are substantially parallel to each other along a common fiber direction. Continuous length fibers are very preferred, although fibers that are oriented and have a length of about 3 to 12 inches (about 7.6 to about 30.4 cm) are also acceptable and are considered "substantially continuous" for the purposes of is
invention.

In the present invention they can be used both thermosetting and thermoplastic resin particles, alone or in combination. Preferred thermosetting materials include epoxides, polyesters, acrylics, polyimides, phenolics, and polyurethanes Preferred thermoplastics include nails, polypropylenes, polyesters, polycarbonates, acrylics, polyimides, polyetherimides, polyaryl ethers, and copolymers of polyethylene and ethylene. Thermoplastic polymers possess environmental resistance, improved fracture toughness and impact resistance in comparison with thermosetting materials. The materials prepreg that have thermoplastic domain arrays They have a long lifespan, and greater resistance to problems of environmental storage. The high viscosity of polymers Thermoplastics does not affect the discontinuous application of the material polymer in fibrous tissue 12. Even for quantities significantly increased, preimpregnated materials Thermoplastics of the present invention are flexible structures. Preimpregnated materials containing domain matrices thermosetting 14 are relatively flexible and adherent before of the reaction.

Domain arrays can contain polymer material from polymer powders, solutions polymer, polymer emulsions, chopped filaments, systems thermosetting resin, and combinations thereof. The applications of these polymeric materials can be by spray, droplets, emulsion, etc. When they used chopped filaments, heat and / or pressure can be used to consolidate the uni-tape and / or a multilayer panel, and chopped filaments should melt at a temperature below that of filaments 16 in the uni-tape. By For example, a flexible structure can be prepared using a 215 denier Spectra® 1000 fiber fibrous fabric 12 together with a Kraton® D1650 powder or with an LDPE (polyethylene) powder low density) or LLDPE (linear low density polyethylene) the molding being carried out at 120 ° C. The need for film of polyethylene, commonly used with simple elements commercial, can be removed as such.

The fibers, pre-molded if desired, can precoated with a polymer material (preferably a elastomer) before placing them in a cellular structure as described above The elastomeric material that can also be used as the die has a tensile modulus, measured at about 23 ° C, less than about 20,000, preferably less than 6,000 psi (41,400 kPa). Preferably, The tensile modulus of the elastomeric material is less than approximately 5,000 psi (34,500 kPa) and most preferably it is less than 2,500 psi (17,250 kPa) to provide efficiency even more improved. The glass transition temperature (T g) of elastomer of the elastomeric material (as evidenced by a sharp drop in ductility and elasticity of the material) is keeps flexible in the field of working conditions, which includes temperatures less than approximately 25 ° C, or less than about 0 ° C. The T g value of the elastomer can be less than about -40 ° C, or less than about -50 ° C, if desired. The elastomer should have an elongation to the breakage of at least about 50%. Preferably, the elongation at break is at least about 100%, and so more preferable, it is about 150%.

Any elastomeric material suitable for the creation of domain matrices can be used for the present invention. Representative examples of suitable elastomers of the elastomeric material have their structures, properties, and formulations together with the cross-linking procedures summarized in the Encyclopedia of Polymer Science, Volume 5, "Elastomers-Synthetic" (John Wiley and Sons Inc., 1964). For example, any of the following materials can be used: polybutadiene, polyisoprene, natural rubber, ethylene-propylene copolymers, ethylene-propylene-diene terpolymers, polysulfide polymers, polyurethane elastomers, chlorosulfonated polyethylene, polychloroprene, polyvinyl chloride plasticized using dioctyl phthalate or other plasticizers well known in the art, butadiene-acrylonitrile elastomers, poly (isobutylene-co-isoprene), polyacrylates, polyesters, polyethers, fluoroelastomers, silicone elastomers, thermoplastic elastomers, and ethylene copolymers. Particularly useful elastomers are block copolymers of conjugated dienes and vinyl aromatic monomers. Butadiene and isoprene are elastomers of preferred conjugated dienes. Styrene, vinyl toluene and t-butyl styrene are preferred conjugated aromatic monomers. Block copolymers incorporating polyisoprene can be hydrogenated to produce thermoplastic elastomers having saturated hydrocarbon elastomer segments. The polymers can be single tri-block copolymers of type ABA, multi-block copolymers of type (AB) n (n = 2-10) or radial configuration copolymers of type R- (BA) x (x = 3-150); where A is a block of a poly (vinyl aromatic) monomer and B is a block of a conjugated diene elastomer. Many of these polymers are commercially produced by Shell Chemical Co. and are described in the "Kraton Thermoplastic Rubber" bulletin,
SC-68-81.

Most preferably, the elastomeric material It contains one or more of the elastomers indicated above. He low modulus elastomeric material may also include loads such as carbon black, silica, glass microballs, etc. up to an amount not exceeding approximately 300% by weight of elastomer, preferably not exceeding approximately 100% by weight, and can be spread with oils and vulcanized using sulfur curing systems, peroxides, metal oxides or radiation, using methods well known to technicians in rubber that have ordinary experience. Mixtures can be used of different elastomeric materials together or can be mixed one or more elastomeric materials with one or more thermoplastics. He high density, low density, and linear low density polyethylene density can be crosslinked to obtain a material of properties appropriate, either alone or in the form of mixtures.

The proportion (percentage by volume) of polymeric material to the fibers or fabrics varies according to the rigidity, shape, thermal resistance, wear resistance, resistance to flammability and other desired properties. Others Factors that affect these properties include density spatial domain matrix, the percentage of pores within of the fibrous tissue, the randomness of the matrix islands, and that other variables of this type related to the situation, the size, shape, positioning and composition of polymeric materials and fibers.

A specific and preferred method of manufacturing The composite material of the present invention is illustrated in Fig. 7. This is a method of manufacturing a composite material that comprises a fibrous tissue in which the fibers are oriented uni-directionally. The filaments 16 are rolled on a polyethylene film 102 to form a fibrous tissue 12. An elastomer latex, thermoplastic elastomer, or precursor thermoplastic for an array of domains 14 is sprayed on the fibrous tissue 12. Once pulverized, fibrous tissue 12 with the domain matrix precursor 14 is fed to an oven 50 to provide bond between fibrous tissue 12 and the precursor of the domain matrix 14. After cooling, a tape is formed uni-directional 52. Solutions can be used polymers similarly. Resins can be sprayed thermosetting and monomers on fibrous tissue 12 and be made react subsequently. You can use masks or templates to control the pattern of domain arrays 14, for example using a series of parallel wires to select continuous lengths that have a narrow width less than 200 µm. Additionally, the geometry used to create flexible structures by the use of Three series of parallel seams, as described in the Patents U.S. No. 5,316,820 and 5,362,527, whose descriptions are incorporated by reference However, any method with any fibrous tissue

Alternatively, a latex can be applied polymer on fibrous tissue 12 and subsequently bind to 12 fibrous tissue with heat and / or pressure. The fiber fabric 12 can contact 200 pressure rollers that feed from containers 202 of latex 208, as demonstrated in Fig. 8. Fibrous tissue 12 is passed through the narrowing between the pressure rollers 200. The pressure rollers 200 they are immersed in the containers 202, and the latex 208 adheres to patterns, such as unbroken lines 204 or points 206, on pressure rollers 200. As the tape uni-directional contacts the 208 latex coated patterns of pressure rollers 200, the polymer is transferred to fibrous tissue 12 to form the matrix islands 18. Fibrous tissue 12, with matrix tapes 18 fixed, it can then be heated, if desired.

Limited amounts of polymers are collected in the fibrous tissue 12. The amounts are such that areas are formed free of polymer in the prepreg, or tape, and the final product obtained from it. Usually the amount of polymer varies from about 50% or less, with preferably about 20% or less, and more preferably about 20% to about 2%, so even more preferably about 15% to about 5%, and very preferably about 10% to about 5% of the area surface of filaments 16 in fibrous tissue 12.

The discontinuous distribution of the composition of Matrix can be reached by other means. For example, this invention includes spot stratification of a fibrous tissue with at least one layer of discontinuous polymer. This could applied by feeding the polymer on the first layer of a discontinuously or by using a perforated layer or pattern in which there are areas without polymer and areas with polymer, it is say holes. The discontinuous polymer layer can stratify with the fibrous tissue under the action of heat and pressure to result in a matrix of discontinuous domains in the fibrous tissue. This results in the fibrous tissue be positionally set by the array of domains in such a way that discrete matrix islands are formed with empty areas between they. The composite material may contain as little as 2 per volume percent resin (matrix) sufficiently distributed to allow fibrous tissue to maintain its integrity despite of the high percentage in fiber volume, or as much as 50 percent in volume of resin distributed sufficiently to leave spaces gaps between the filaments of the fibrous tissue.

The matrix can be applied to the fibrous tissue of various ways, such as in liquid form, in the form of a adherent solid or suspended particles, or as a bed fluidized Alternatively, the matrix can be applied as a solution or emulsion in a suitable solvent that does not affect unfavorably to the properties of fibrous tissue. Suitable applications of the die include stamping, spraying, liquid sludge, powders by electrostatic methods and / or other suitable matrix applications, being able to determine the type of application of a particular situation by experts in The technique. While any liquid capable of dissolve or disperse the matrix polymer, solvent groups Preferred include water, paraffinic oils, ketones, alcohols, aromatic solvents or hydrocarbon solvents including of paraffin oil, xylene, toluene and octane. The techniques used to dissolve or disperse matrix polymers in solvents will be those conventionally used for the coating of similar elastomeric materials on a diversity of substrates.

Other techniques can be used to apply the polymer (matrix) to the fibers, including the coating of the high modulus precursor (gel fiber) before operations high temperature stretching, either before or after fiber solvent removal. Fiber can stretch then at elevated temperatures to produce the coated fibers. The gel fiber can be passed through a solution of the appropriate coating polymer (the solvent can be oil of paraffin, an aromatic solvent or an aliphatic solvent) in suitable conditions to achieve the desired coating. The crystallization of high molecular weight polyethylene in fiber gel may or may not have occurred before fiber tissue go to the cooling solution.

Fibers and cell structures produced from them are made of composite materials as the precursor or prepreg material to prepare the composite items. The preimpregnated materials of low surface density of the present invention can be use to create consolidated panels that provide a excellent ballistic protection. The term composite material has by object mean combinations of fiber or fabric with material polymer in the form of matrix islands, which may include other materials such as fillers, lubricants or the like as has been indicated above in this report.

Additional methods to fix the matrices of domains 14 may include, without limitation, hot melt, solution, emulsion, liquid sludge, surface polymerization, fiber rapport, interleaving of films, electroplating, and / or dry powder techniques.

Composite materials can be built and arrange in a variety of ways. It is convenient to characterize the geometries of such materials composed of the geometries of the fibers A suitable arrangement of this type is a plurality of layers of laminates in which the coated fibers are arranged in a laminar system and aligned parallel to each other others along a common direction of the fibers. Layers successive of such uni-directional fibers Coated may be rotated with respect to the previous layer. A example of such laminate structures are materials compounds with the second, third, fourth and fifth layers rotated + 45º, -45º, 90º, and 0º, with respect to the first layer, but not necessarily in that order. Other examples include materials Compounds with alternating layers rotated 90º ones with respect to others, e.g., 0/90, + 45 / -45, + 30 / -60, etc. The present invention includes composite materials that have a plurality of layers. There may be 1 to 500, preferably 2 to 100 and more preferably 2 to 75 layers.

The normal technique to form stratified includes the steps of arranging coated fibers in a structure desired cell, and then consolidate and heat the overall structure to make the coating material flow and occupy a portion of the empty spaces, thus producing a continuous matrix. Another technique is to arrange layers or other structures of Coated or uncoated fiber adjacent to and between different shapes, e.g. films, of the parent material and consolidate and then harden by heating the overall structure. In the Previous cases, it is possible that the matrix can stick or flow without melt completely. In general, if the matrix material is heats only to a point of adhesion, it will be required generally more pressure. Also, the pressure and time to harden the composite material and achieve optimal properties they will generally depend on the nature of the matrix material (chemical composition and molecular weight) and the temperature of processing For the purposes of the present invention, you must remain a substantial empty volume (free of matrix).

Multiple tapes containing the material compound 10 of the present invention may be combined with others. U.S. patents No. 5,061,545 and 5,093,158 describe various combinations of two-layer composite materials in the which fibers of each layer are fibers uni-directional. The fibers of adjacent layers they are described as forming an angle of 45º to 90º ones with respect to others, the preferred angle between the fibers in the layers adjacent approximately 90º from one to another. The descriptions of U.S. patents No. 5,061,545 and 5,093,158 are incorporated into this memory by reference.

The composite materials of the present invention may possess extraordinarily fiber content high from 90 to 98 percent in volume and have ballistic efficiency improved compared to composite materials that have a continuous polymer matrix.

Experimental procedures

He passed TO

Preparation of dry fiber fabrics

A thread was wound on a rotating drum of A filament winder. The drum was 30 inches (76 cm) in diameter, 48 inches (122 cm) in length, and was covered with Halar® film, a copolymer of chloro-trifluoro-ethylene and ethylene, a product manufactured by AlliedSignal Specialty Films of Pottsville, Pennsylvania, before winding. Strips of 2-inch (5.08 cm) wide double adhesive tape parallel to the drum shaft at 10-inch intervals (25.4 cm), from center to center. The thread was wound on top of the tape. Be applied simple masking tape (coated) over the double duct tape covered with the thread to ensure that All filaments held their place. The Halar® film covered with the thread detached from the drum and cut along of the center line of each tape. The result was a supply of parallel dry threads, 8 inches (20.3 cm) of Length, reinforced by Halar® film and held in place per 1 inch (2.45 cm) wide tape at each end.

B. Preparation of protection panels experimental

The 8-inch (20.3 cm) sections of length of step A above, were placed on top of a sheet metal and were fixed in place with masking tape to keep Straight threads A matrix resin was applied (see examples for details), and a second 8-inch section (20.3 cm) over the first section of 8 inches (20.3 cm), which spun 90 degrees with respect to fiber orientation, with the Halar® film on the top. An aluminum sheet 1/8 inch (0.3175 cm) thick, 7.5 inches x 7.5 inches (19 cm x 19 cm), focused on the threads and the whole put in a hydraulic press at 120 ° C, with a force of 3 tons, for 10 minutes. The sheet metal acted as spacer to release the press plates from the tapes that They surrounded the fiber tissues.

C. Measurement of Panel Flexibility

For application in protective equipment body, the panels of the present invention should have a flexibility similar to or greater than fabric structures with conventional ballistic resistance. A simple essay for determining a measure of flexibility is to put a panel square on a flat surface and let one side stand out by an edge (with the side of the panel parallel to the edge) in a length (l). The vertical distance (h) for the surface is measured flat to the unsupported side of the panel, and the value is calculated (h / l). When h / l is equal to l, the panel is very flexible, and when h / l is equal to zero, the panel is very rigid. To compare the flexibility of a panel with that of a control fabric, it is calculated percentage flexibility such as:

100% x (h / l) panel / (h / l) fabric =% flexibility.

For body protection equipment, it is desirable that the panels have a percentage flexibility from about 50% to about 150% of the woven fabric with ballistic resistance of control without matrix, preferably from about 70% to about 150%, and more preferably from about 85% to about 150%, as described later in example 10.10. Preferably, the h / l value is of about 0.7 or greater, more preferably since approximately 0.85 or greater.

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Example 1

Spectra® 1000 fibers (215 denier, 60 filaments per tip), commercially available from AlliedSignal Inc. of Petersburg, Virginia (40 tips per inch (EPI) and density nominal surface (AD) of 0.00376 g / cm2), and a matrix resin Kraton® rubber type G1650, granular, manufactured by Shell Chemical Co. of Houston, Texas (particles were passed through a # 30 sieve, of 600 micrometers or 0.0234 inches) was used in the experimental procedure indicated above. Resin matrix was used with 7.5% by weight (total) dispersed over the bottom fabric before cross bending. After molding, the matrix resin became filament islands connected by points within the fiber cord, and between the fiber cords. The panel was initially paper-like, but resembled the flexibility of a fabric after curling and bending.

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Example 2

Example 1 was repeated with a matrix resin of 15% by weight. The results were the same as in Example 1; however, the panel was more robust and more resistant to de-stratification.

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Example 3

Example 1 was repeated with a matrix resin of 20% by weight and an added layer of polyethylene film, of 0.00035 inches (0.000889 cm) thick, manufactured by Raven Industries of Sioux City, South Dakota, was applied outside of both fiber bands (the Halar® film was removed, and a release paper on the PE film before press it). The paper had a robust structure with flexibility satisfactory

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Example 4

They were used in the experimental procedure indicated above Spectra® fibers, 1000/215/60 (40 tips per inch (EPI) and nominal surface density (AD) of 0.00376 g / cm2) and a matrix resin of Prinlin B7137X-1, an aqueous dispersion of Kraton® D1107 rubber, manufactured by Pierce & Stevens of Buffalo, New York. Both fiber bands are sprayed with fine droplets of Prinlin and dried before molding, giving 85 percent by weight fiber. The panel was initially paper-like, but it resembled flexibility to a fabric after curling and bending.

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Example 5

They were used in the experimental procedure indicated above Spectra® 1000/215/60 fibers (40 tips per inch (EPI) and nominal surface density (AD) of 0.00376 g / cm2) and a diluted matrix resin of 3 parts of water and 1 part of Prinlin B7137X-1, in the procedure experimental indicated above. Both fiber bands are they sprayed with fine droplets of Prinlin that dried before molding, giving 95 percent by weight fiber. The panel was initially paper-like, but it resembled flexibility to a fabric after curling and bending. The panel was less robust than the panel in Example 4.

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Example 6

They were used in the experimental procedure indicated above Spectra® 1000/215/60 fibers (40 tips per inch (EPI) and nominal surface density (AD) of 0.00376 g / cm2) and a powder matrix resin of S3DSBK polyethylene roto-molding, 120 µm / fine, manufactured by PFS Thermoplastic Powder Coatings Inc. of BigSpring, Texas. PE was sprinkled on the fiber belt lower before cross bending, estimating the amount of PE after molding as 14% by weight of the total weight. The panel was initially similar to a role, but it became similar to a fabric with manipulation. There was a low surface friction.

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Example 7

Spectra® 1000/215/60 fibers (40 tips per inch (EPI) and nominal surface density (AD) of 0.00376 g / cm2) and a single 0.00035 polyethylene film inches (0.000889 cm) thick, manufactured by Raven Industries, was placed between the two fiber bands to serve as a control for Example 6. The panel was less flexible than the Example panel 6, but it was considered useful.

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Example 8

Spectra® 1000/215/60 fibers were used (40 tips per inch (EPI) and nominal surface density (AD) of 0.00376 g / cm2) without any matrix resin. After molding, the panel exhibited a paper-like quality, and came off when It was manipulated.

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Example 9

Spectra® 1000/1300 fibers, 240 filaments per tip, a product of AlliedSignal Inc., (9.25 tips per inch (PPE) and nominal surface density (AD) of 0.005266 g / cm2), were sprayed with a Prinlin matrix resin B7137X-1 and were processed according to the experimental procedure indicated above, with drying before of molding, to give 78 percent by weight of fiber. The panel was significantly more flexible than fiber matrix products continuous similar, which had a surface density of fibers equivalent.

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Example 10

Examples 10.1-10.3

Elastomeric monofilaments were created thermoplastics by extrusion of a mixture of two elastomers thermoplastics (Kraton® G1652 and 1657) in the weight ratio of 2: 1. 650 and 1300 denier elastomeric fibers were formed in tapes uni-directional as follows: Movie was arranged Halar® in a drum with 2-inch double-sided adhesive tape (5.08 cm) width set at 19-inch intervals (48.26 cm), from center to center, along the longitudinal direction. The thermoplastic elastomer fibers were wound to give 4.6 tips per inch (1.81 tips / cm) wide. Adhesive tape was arranged single-sided on the position of the double-sided tape to anchor the fiber tips in place. The anchor straps are cut in half, giving 17-inch (43.18 cm) bands of uni-directional fiber mat length usable in which the filaments were held together by strips of insulated rubber. The bands were cut at intervals of 17 inches (43.18 cm) along the longitudinal direction to produce 17-inch (43.18 cm) squares of fiber mat uni-directional that had a separation considerable between monofilaments. Fiber tapes were prepared Spectra® uni-directional in the same way, except that the 1300 denier Spectra® 1000 material was wound with 2.6 tips per inch (1.02 tips / cm) on the drum. They prepared composite panels stabilized by cross bending a rubber mat with a Spectra® tape and molding thereof together at 100 ° C for 5 minutes at a pressure of 10 tons per square foot (1,076 x 10 5 kg / m2). Panels stabilized bent cross, the Halar® film was removed, and the panels were then molded together (under the same conditions used to build the uni-directional tape stabilized), with resin-rich sides of the tape uni-directional stabilized facing each other. The results are shown below in Table 1.

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TABLE 1 Comparative ballistic shielding efficiency flexible for a surface density of 1 kg / m2 against bullets 0.38 gauge lead - grid reinforcement rubber

one

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The comparison of 10.1 and 10.2 shows that the fiber grid is more effective for the same weight percentage of elastomeric grid. An additional amount of elastomeric grid causes the panels to become rigid and less effective ballistically (10.3). The results indicate that the percentage in weight and grid size need to be optimized for a Optimal protection against a specific threat.

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10.4: Example comparative

A comparative example of a fiber band Parallel (a product of AlliedSignal and sold under the name single element commercial Spectra Shield®, 1300 denier wire Spectra® 1000 fibers, 240 filaments per thread) is coated with a Kraton® D1107 solution in cyclohexane. This material covers evenly the band of parallel fibers that passes through a drying chamber to remove the solvent to produce a uni-directional tape material. This material is subjected to cross bending and polyethylene film is stratified on the upper and lower surfaces in order to prevent the panels stick together. The surface density of the panel, the fiber, matrix, and PE film were 0.147, 0.105, 0.0262, 0.0157 kg / m2, respectively. PE movie had a point melting 114 ° C.

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10.5

A Halar® film, manufactured by AlliedSignal Specialty Films, wound around a 4-foot drum (121.92 cm) in length and 30 inches (76.2 cm) in diameter. The drum is spun and wrapped Spectra® 1000 fiber (1300 denier) at 9.26 tips per inch (3.65 tips / cm). The fiber band was pulverized  with a latex (Kraton® D1107: resin in weight ratio 3: 1 mark Prinlin B7137X-1, a product of Pierce and Stevens). This uni-directional tape, along with the backing of Pull, cut into 15-inch (38.1 cm) squares and folded cross 0/90 with the latex inside. The panel was then molded to 125 ° C for 15 minutes at 10 tons / ft 2 (1,076 x 10 5 kg / m2) giving 81 percent by weight fiber. The Halar® film and polyethylene film (the same as it was used in Example 10.4) outside panel 0/90, and the Total assembly was molded as previously described, except The molding time was 2 minutes.

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10.6

This sample was built parallel to the Example 10.5, except that a polyethylene film was wrapped (identical to the film applied on the panels of Example 10.5) on a metal drum (4 feet (121.92 cm) in length and 30 inches (76.2 cm) in diameter and a latex was sprayed on its surface in circular elastomer domains that had a bandwidth of 125 to 250 µm and covering approximately 25% of the surface of the film. The spraying process is carried out with a Wagner Power Painter instrument - Model 3.10, using a 0.8 mm nozzle. The spraying began in a end of the rotating drum and advanced to the other end, producing individual circular domains of Kraton D1107. The Spectra 1000 fiber was wound identically to that described in the Example 10.5. A uni-directional tape was produced robust A series of 0/90 panels that had fiber were molded of polyethylene on the surface. The molding was carried out at 80 ° C, 95 ° C, 105 ° C and 130 ° C, for 15 minutes at 10 tons / ft2 (1,076 x 10 5 kg / m2). As the molding temperature, the panels became more paper-like and less like cloth in flexibility. A 0/90 panel was molded against a set of washers (0.075 inches (0.191 cm) of thickness, outside diameter 0.87 inches (2.21 cm), and diameter inside 0.37 inches (0.94 cm)). The panels were stamped on forms of fully consolidated washers. This proved that consolidation patterns can be generated from the panels of this invention. You can build structures of Useful domains to provide continuous lines that bend easily (such as sets of equilateral triangles). Eight panels, molded at 95 ° C, were designated as Example 10.6 and were rehearsed against 0.38 caliber lead bullets. Additionally, it he arranged a panel in a dot junction mold that had a square grid with circular section enhanced at intersections of grid. The circular sections were 1.0 mm in diameter and the distance from center to center was 7 mm. The panel was placed in a press at approximately 500 psi (3,450 kPa) and molded for 150 seconds at 115 ° C. The panel remained flexible. Obviously, a great diversity of patterns can be created by This molding technique.

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10.7

This sample was created in the same way as the Example 10.6, except 1500 aramid fiber was wound denier, Twaron fiber (a product of Akzo, 1450 denier thread, from 1.5 denier per filament, tensile strength 24.4 g / denier, module 805 g / denier) on the rotating drum, 8.03 tips per inch (3.16 tips / cm). Circular domains were created in the polyethylene film analogously to those in Example 10.6. The domains created by spraying on the fiber web are they also distorted in the same way as in Example 10.6. Scanning electron microscopy indicated that the domains Coated were discontinuous. The domains were much longer in the direction parallel to the length of the fibers (l), with dimensions ranging from 150 µm to 500 µm in this address. The L / D ratio varied from 3 to 1 to 25 to 1 for These domains

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10.8

Thermoplastic elastomeric fibers were created by extrusion of a mixture of Kraton® G1652 and 1657 in the ratio of 2: 1 weight. Uni-directional tapes were formed made with elastomeric fibers (650 denier) in the way next:

Elastomeric monofilaments were created thermoplastics by extrusion of a mixture of two elastomers thermoplastics (Kraton® G1652 and 1657) in the weight ratio of 2: 1. 650 and 1300 denier elastomeric fibers were formed in uni-directional tapes as follows: It was arranged Halar® film on a drum with double-sided adhesive tape 2 inches (5.08 cm) width set at 19-inch intervals (48.26 cm), from center to center, along the direction longitudinal. Thermoplastic elastomer fibers were wound to give 4.6 tips per inch (1.81 tips / cm) in width. Be fixed single-sided adhesive tape over the position of the tape Double-sided to anchor the fiber tips in place. The anchor straps were cut in half giving bands with 17 inches (43.18 cm) of fiber length uni-directional usable, in which the Filaments are held together by insulated rubber strips. The bands were cut at intervals of 17 inches (43.18 cm) at length of the longitudinal direction to produce squares of 17 inches (43.18 cm) of rubber fiber mat uni-directional that had considerable spacing between monofilaments. Spectra® fiber tapes were prepared uni-directional in the same way, except that it wound the Spectra® 1000 material of 1300 denier 2.6 points per inch (1.02 tips / cm) on the drum. Panels were prepared compounds stabilized by cross bending of a mat rubber with a Spectra® tape and molding them together at 100 ° C for 5 minutes at a pressure of 10 tons per foot2 (1,076 x 10 5 kg / m2). The stabilized panels then folded in cross, the Halar® film was removed, and subsequently molded  the panels together (under the same conditions that were used to build the uni-directional tape stabilized) with resin-rich sides of the tape uni-directional stabilized facing each other other.

Fiber tapes were prepared in the same way Spectra® uni-directional, except that the material Spectra® 1000 of 1300 denier was wound at 9.26 tips per inch (3.65 tips / cm) on the drum.

Tape panels were prepared uni-directional stabilized by cross bending of a rubber panel with a Spectra® panel and molding thereof together at 100 ° C for 5 minutes at 10 tons per foot2 (1,076 x 10 5 kg / m2). These uni-tapes stabilized bent cross, the Halar® film was removed, and the panels were then molded together using the same conditions that used to build the uni-tape stabilized, with the sides rich in stabilized uni-directional tape resin one against other.

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10.9: Water vapor transmission

The relative ability to transmit steam of water through a panel of this invention (Example 10.3), compared to the Spectra Shield® material, it was determined by setting 15 grams of water in a 2-ounce wide mouth jar (59 ml) (inner diameter 42 mm) and weight loss record in 24 hours at room temperature and 50 percent humidity relative. The panels were fixed to the jars using tape Double adhesive around the jars. A cloth was also tested ballistic Spectra® 1000 (Style 955-215 denier, de smooth ligament of 55 x 55 tips / inch (21.7 x 21.7 tips / cm)). The structures of the present invention clearly convey the water vapor at rates similar to fabric. The data is shown to continued in Table 2.

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TABLE 2 Water loss comparison

2

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10.10: Flexibility

Comparison of the flexibility of the Simple commercial element, grid reinforced panel (Example 10.3) and a commercial woven fabric Spectra® 1000 (Spectra® 1000/45 x 45 tips / inch (17.32 x 17.72 tips / cm) of 215 denier fabric flat, a product of Clark Schwebel). The sample was placed on a flat surface and allowed to hang from the edge in a length (l) of 13 cm The distance (h) below the surface was determined flat free side. The greater the distance (h) the more Flexible is the structure. As you can see from Table 3 next, the nonwoven panel with the grid was even more flexible than a woven ballistic fabric of Spectra® 1000. The samples are flexed before testing them to simulate exhaustion physical ("distressing").

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TABLE 3 Comparison of the flexibility of panels

3

Example 11

11.1

A Halar® film, manufactured by AlliedSignal Specialty Films, wound around a 4-foot drum (121.92 cm) in length and 30 inches (76.2 cm) in diameter. They were applied strips of double adhesive tape 2 inches (5.08 cm) wide at along the length of the drum at 8-inch intervals (20.32  cm). The drum was spun and Spectra® 1000 fiber (1300) was wound denier) at 9.26 points per inch (3.65 points / cm). After the Spectra® 1000 wire winding, 2 inch strips were applied (5.08 tips / cm) of masking tape width over the areas covered by double adhesive tape in order to anchor Firmly fibers in place. The adhesive tapes, along with Halar® film and Spectra® fiber were cut along the center line of the adhesive tape to produce mats with fiber lengths of 8 inches (20.32 cm) and width of 48 inches (121.92 cm). The mats were subsequently cut to sizes suitable for use with elastomeric fibers. Be prepared an elastomeric monofilament fiber of Kraton® G1650 (2212) denier by extrusion of the polymer through a row of 0.02 inches (0.051 cm) at 260 ° C using a capillary rheometer Instron The parallel fiber band, 8 inches (20.32 cm) in box, it was attached with adhesive tape to a metal plate and applied double adhesive tape on both sides of the band with the length of the tape parallel to the longitudinal direction of the fibers. The Kraton® G1650 fibers extended perpendicular to the fiber direction and anchored to the tape on both sides of the band at intervals of 1 cm.

Tapes were prepared robust uni-directional molding between plates metal with Halar® film on one side and subsequent removal of the same after molding at 125 ° C at low pressure in a press hydraulics. The ribbons were folded cross and molded again to create 0/90 panels that had a total area density of 0.154 kg / m2 and 32 weight percent matrix. The width of the Deformed Kraton® G1650 fiber was approximately 3 mm, corresponding to an area coverage of 49 percent. After With some initial flexion, a soft low friction panel was created. Deformation of the fibers occurred during the molding process Spectra®, the pores were removed, and the initial stiffness was high, in Comparison with the flexed material.

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11.2

This sample was identical to Example 11.1, except that the Kraton® fiber crumbled in lengths of 3 cm that randomly arranged on the fiber band. This one was molded then to produce a uni-directional tape. He Kraton® G1650 material flow caused significant deformation in the fiber band, an undesirable feature.

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11.3

This sample was similar to Example 11.1, except that the elastomeric fiber was 275 denier Kraton® G1651, which was extruded through a row of 0.007 inches at 260 ° C. Both the uni-directional tape and the 0/90 panel The resulting folded cross had 5.5 percent matrix weight. The surface density of the 0/90 panel was 0.1113 kg / m2. The elastomeric fiber widened to less than 1 mm, resulting in that 20 percent of the panel area had coverage elastomer

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11.4

This sample was similar to Example 11.1, except elastomeric fibers (Kraton® G1651 811 denier) were oriented at 45 degrees from the longitudinal direction of Spectra® fibers. The elastomeric fiber was extruded through a row of 0.012 inches (0.0305 cm) at 260 ° C. Both tape uni-directional as the 0/90 cross folded panel resulting had 20 percent matrix weight. Two were possible different structures, with elastomeric fibers forming a diamond figure or a series of lines parallel to 45º with respect to the length of Spectra® fibers. When resin rich sides they were pressed together, the final molded panel was consistent and had Very low friction

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Example 12

Tapes were prepared as follows: applied on a 0.00035 inch PE film drum (0.000889 cm) thick, manufactured by Raven Industries of Sioux City, South Dakota; the drum was spun and latex was sprayed on the surface of the film forming a dispersion of statically uniform droplets. It was then wound on the drum Spectra® 1000/650 denier fiber, 240 filaments per tip, and band Spectra® fiber was sprayed with latex.

These tapes were robust enough to be manipulated in order to prepare a final cross bent panel Suitable for bulletproof vest applications. Ribbons uni-directional bent cross (0/90) and be molded in different conditions. Cross bent panels they generally showed a combination of flexibility satisfactory with satisfactory ballistic efficiency. Panels cross bent showed that the control of the amount of matrix, consolidation and distribution can be adapted with properties to apply to a particular use.

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12.1

A band of parallel fibers was coated evenly with a solution of Kraton® D1107 in cyclohexane, and was then passed through a drying chamber to remove the solvent in order to produce a tape material uni-directional This material was folded in a cross and Stratified 0.00035 inch (0.000889) polyethylene film cm) thick, manufactured by Raven Industries of Sioux City, South Dakota, on the upper and lower surfaces in order to prevent that the panels stick together. Molding conditions they were 120 ° C for 10 minutes. The surface density of the panel, the fiber, the matrix, and the PE film were 0.147, 0.105, 0.0262 and 0.0157 kg / m2, respectively. The PE movie had a melting point of 114 ° C. The polyethylene film provided weight and stiffness on the matrix of Kraton® D1107, alone.

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12.2: Matrix present as discrete thermoplastic domains

A Halar® film (a product of AlliedSignal Specialty Films of Pottsville, PA) was wound around a drum (4 feet (121.92 cm) in length by 30 inches (76.2 cm) of diameter). The drum was rotated and Spectra® fiber was wound 1000 (1300 denier), at 9.26 points per inch (3.65 points / cm). The fiber band was sprayed with a latex (Kraton® D1107 and Prinlin B7137X-1, a product of Pierce and Stevens in 3: 1 weight ratio). This uni-directional tape, together with the back of Halar® it was cut into squares of 15 inches (38.1 cm) and folded cross 0/90 with the tape on the inside. The folded cross material was then molded at 125 ° C for 15 minutes at 10 tons / ft 2 (1,076 x 10 5 kg / m2). The Halar® film was removed and a film was applied polyethylene (identical to the film used in the Example 12.1) on the outer surfaces of panel 0/90, and the assembly total was molded identically to the first molding, except that the Molding time was 2 minutes. 8 panels were superimposed together 15-inch squares (38.1 cm), were immobilized and tested against a clay backing using caliber lead bullets 0.38 (158 grains) (10.24 g). The value V_ {50} was 824 ft / s (251.2 m / s).

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12.3

Kraton® D1107 and Prinlin matrix domains with PE film (matrix domains were pulverized) 8 panels,% by weight of fiber at 81 percent ADT = 1.04 kg / m2

This sample was constructed similarly to Example 12.2, except that a polyethylene film (identical to the film applied on the surface of the panels of Example 12.2) was wound on a metal drum (4 feet long and 30 inches in diameter ) and a latex was sprayed on its surface (the surface density of the Kraton® / Prinlin material sprayed on the surface was 0.0019 kg / m2). Circular elastomer domains were created within the plane of the tape in the range of sizes from 125 to 250 µm and covering approximately 25 percent of the film surface. The spraying process was carried out with a Wagner Power Painter - Model 310 instrument using a 0.8 mm nozzle. Spraying started at one end of the rotating drum and advanced to the other end, producing individual circular matrix domains. Spectra® 1000 fiber was wound in an identical manner to that described in Example 12.2, and the fiber mat was also sprayed in a similar manner to Example 12.2. This produced a robust uni-directional tape with the removal of a detachment backing. A series of 0/90 panels were molded with the polyethylene film on the surface. The molding was carried out at 80 ° C, 95 ° C, 105 ° C and 130 ° C for 15 minutes at 10 tons / ft 2 (1,076 x 10 5 kg / m2). As the molding temperature increased, the panels became more paper-like and less like fabric in flexibility. The molded panel at 95 ° C was flexed a few times and evaluated for flexibility in a manner as described in Example 10.10. The panel had a flexibility of 0.96 and a flexibility percentage of 114 percent compared to the ballistic fabric ( see Example 10.10).

A 0/90 panel was molded against a set of washers (0.075 inches (1.91 mm) thick, outside diameter 0.87 inches (22.1 mm) and inside diameter 0.37 inches) (9.40 mm). Washer figures were completely stamped on the panel consolidated. This showed that patterns of consolidation from the panels of this invention. They can easily build useful domain structures, which provide continuous lines that can be easily folded (such as sets of equilateral triangles).

Eight of the molded panels at 95 ° C are rehearsed against 0.38 caliber lead bullets. Additionally, it he arranged a panel in a dot junction mold that had a square grid with circular domains enhanced in the grid intersections (the circular sections were 1.0 mm in diameter and the center to center distance was 7 mm). He panel was arranged in a press at approximately 500 psi (3,450 kPa) and molded for 150 seconds at 115 ° C. Domains circulars were consolidated (approximately 1.6 percent of area) and the remaining areas remained unbound. The panel is kept flexible.

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12.4

This sample was prepared as described in the Example 12.3.

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TABLE 4 Comparative ballistic shielding efficiency flexible against 0.38 caliber lead bullets

4

Example 13

The following structures were investigated:

A. Spectra Shield® single element material

This structure, which incorporates material prepreg 0/90, requires PE film on top and lower to prevent the fusion of the panels due to the matrix adhesiveness (Kraton® D1107). The panels are consistent and have a relatively low fiber weight% (72 per hundred). The sandwich construction prevents flexibility, as shown in Table 5.

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B. Minor modification of the simple element for improved efficiency

The basic idea is to use matrix domains in replacement of the array of continuous matrix in the product commercial A, in order to get more flexibility. This was done spraying a Kraton® D1107 latex through a sprayer of paint on a band of fibers in a rotating drum, giving a statistically uniform distribution. The process was very simple producing domains on the surface of the mat fibers The resin-rich surfaces were adapted, and applied PE film on the top and bottom. He assembly was molded to produce flexible panels that superimposed to make ballistic targets, giving an 81 per Weight percent fiber. With reference to Table 5, it will be observed that ballistic efficiency (SEAT) is approximately 1.3 times the of the commercial control (A), and that the percentage by weight of fiber is substantially higher than for the commercial product.

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C. Matrix-PE powder designed for rotational molding

The optimal ballistic results were obtained With this system. A linear low density polyethylene powder (T m = 105 ° C) was pumped in the form of liquid sludge onto a fiber mat in a rotating drum. The 0/90 panel manufactured from that it was flexible and had low surface friction. The advantages of PE powders were its low cost and solvent-free manufacturing With reference to Table 5, the ballistic efficiency (SEAT) was excellent compared to the control sample A.

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D (1) -D (2). EPDM / PE powder matrix in 1: 4 weight ratio

Some difficulties were encountered in the manufacture of parallel fiber bands with PE powder due to that the powder did not adhere to the fiber on the drum and tended to break off. It was discovered that a liquid mud of PE powder in an EPDM solution adhered perfectly to the mat of fibers in the rotating drum. However, ballistic efficiency It was not as satisfactory as the one obtained when it was used exclusively PE powder.

Table 5 summarizes the ballistic effectiveness of these experimental materials, based on SEAT values.

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TABLE 5 Comparative ballistic shielding efficiency flexible against 0.38 caliber lead bullets

5

Example 14

A flexible target reinforced with aramid fiber as described in Example 12.3. It was used Twaron fiber (a product of Akzo, 1450 denier thread, 1.5 denier per filament, tensile strength 24.4 g / denier, module 805 g / denier) replacing the Spectra® 1000 yarn and wound on the Drum at 8.3 turns per inch (3.27 turns / cm). The target, which had 7 panels 0/90 with ADT = 0.995 kg / m2, it was tested ballistically against a 0.38 lead bullet. The value V_ {50} was 924 ft / s (281.6 m / s) and the SEAT value was 408 J-Kg / m2. The structure provided a satisfactory ballistic protection.

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Example 15

15.1

A Halar® film (a product of AlliedSignal Specialty Films, Pottsville, PA) reels around a drum 4 feet (121.92 cm) in length by 30 inches (76.2 cm) of diameter. The drum is rotated and PBZO fiber is wound (1300 denier) with 9.26 tips per inch (3.65 tips / cm). The band fiber is sprayed with a latex (Kraton® D1107 and Prinlin B7137X-1, a product of Pierce and Stevens in 3: 1 weight ratio). This uni-directional tape, together with the back of Halar®, it is cut into squares of 15 inches (38.1 cm) and bends cross 0/90 with the ribbon inside. The folded cross material is then molded at 125 ° C for 15 minutes at 10 tons / ft 2 (1,076 x 10 5 kg / m2). The Halar® film is removed and a film is applied of poly-ethylene on the outer surfaces of the panel 0/90, and the total assembly is molded. 8 panels overlap 15-inch (38.1 cm) squares together, are immobilized and rehearse against a clay backing using lead bullets from 0.38 caliber (158 grains) (10.24 g). Hopefully the value V_ {50} is greater than a similar amount of PBZO fiber in a Conventional Shield style product.

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Example 16

16.1

A Halar® film (a product of AlliedSignal Specialty Films, Pottsville, PA) reels around a drum, 4 feet (121.92 cm) in length by 30 inches (76.2 cm) of diameter. The drum is rotated and PBZT fiber is wound (1300 denier) with 9.26 tips per inch (3.65 tips / cm). The band of fiber is sprayed with a latex (Kraton® D1107 and Prinlin B7137X-1, a product of Pierce and Stevens in 3: 1 weight ratio). This uni-directional tape, together with the back of Halar® it is cut into 15-inch squares (38.1 cm) and folds cross 0/90 with the tape inside. He cross folded material is then molded at 125 ° C for 15 minutes at 10 tons / ft 2 (1,076 x 10 5 kg / m2). The movie Halar® is removed and a polyethylene film is applied over the outer surfaces of panel 0/90, and the assembly is molded total. 8 square panels of 15 inches (38.1 cm) overlap together, they are immobilized and tested against a clay backing using 0.38 caliber lead bullets (158 grains) (10.24 g). Is if the value V_ {50} is expected to be greater than a similar amount PBZT fiber in a conventional Shield style product.

The summary, description, examples and drawings of the invention above should not be construed as limitations, but are only illustrative of the characteristics of the invention defined in the claims.

Claims (7)

1. An article designed to resist ballistic impacts, selected from a bulletproof vest, a helmet and body protection equipment, comprising a composite material (10) comprising a fibrous tissue that is a layer of a plurality of filaments (16) attached -directional and a plurality of matrix islands (18), each of said matrix islands (18) connecting at least two filaments (16), said matrix islands (18) holding together the plurality of filaments (16) in a unitary structure, characterized in that each of said matrix islands (18) has an average size smaller than about 5 mm and in which the filaments (16) are filaments selected from the group consisting of ultra-high molecular weight polyethylene, molecular weight polypropylene ultrahigh, aramid, polyvinyl alcohol, polyacrylonitrile, polybenzoxazole, polybenzothiazole and combinations thereof. 2. The article of claim 1, in the which the volume ratio of matrix islands (18) to the plurality of filaments (16) is approximately 0.4 or less. 3. The article of claim 2, in the which the volume ratio of matrix islands (18) to the plurality of filaments (16) is approximately 0.25 to approximately 0.02. 4. The article of claim 3, in the which the volume ratio of matrix islands (18) to the plurality of filaments (16) is about 0.2 to about 0.05 5. The article of claim 1, in the which domain matrix provides a filament structure robust 6. The article of claim 1, in the which the average size of the matrix islands (18) is less than 3 mm in a planar dimension. 7. The article of claim 1, in the which the average size of the matrix islands (18) is less than 1 mm in a planar dimension.